The morning of May 16 began like many others. Carrying hammers and rucksacks, hundreds of Tanzanian villagers trudged to the mountain of waste rock at dawn expecting to make another illicit deal with the heavily armed police who protect it.

Two hours later, at least five villagers were dead and many others wounded – gunned down by police at the gold mine owned by a subsidiary of Barrick Gold Corporation of Toronto.

The shooting, the latest in a series of deadly incidents at the mine over the past several years, raises troubling questions about Barrick’s security agreement with a notoriously corrupt police force that routinely extracts bribes from the villagers who enter the North Mara mine to scavenge for traces of gold.

It also provokes questions about Barrick’s decision to keep operating in the anarchic conditions around its mining site, where violent confrontations are common, allegations of police abuses are frequent and deaths are inevitable.

During a five-day visit to the North Mara Mine and the surrounding villages, The Globe and Mail witnessed an atmosphere of conflict and intimidation. Interviews with injured survivors of the May 16 shootings and other witnesses suggest that most of the villagers were unarmed or carrying only stones when they were shot. The witnesses, along with the local police commander, have contradicted the company’s assertion that hundreds of people attacked the police with machetes, hammers and rocks.

The interviews also documented the widespread corruption of police at the mine, which the company is now investigating. African Barrick Gold, which is 74-per-cent owned by Barrick Gold Corp., confirmed to The Globe and Mail that it is investigating “whether employees and police have participated in a fraudulent scheme of accepting money for access to the site by illegal miners.” It said it has “provided these allegations to the police.”

According to police, there were 800 to 1,200 villagers at the mine on May 16. The number of scavengers was larger than usual because of information that the waste rock on that day would include high-quality rocks – information that is routinely passed on to the scavengers by mine employees and by the police themselves, according to the villagers and the Tanzanian media.

Normally, villagers say, the police accept bribes of up to several dollars a person in exchange for allowing them onto the mine site, but the bribes can be paid only when the villagers enter in small groups – so on May 16 the police were trying to break the scavengers into small groups. When they refused, the police fired into the air, and then began shooting directly at the villagers, witnesses said.

The police are investigating whether their officers were justified in opening fire on May 16, and in a series of earlier shootings at the mine. Barrick is also asking the police to investigate allegations of sexual assault by about a dozen police and security guards at the mine.

In every case, however, the police will be investigating themselves – something that is unlikely to reassure the 68,000 people in the villages around the mine, who see the police as corrupt and dishonest.

The facts of the May 16 shootings – and even the casualty numbers – are still in dispute. The police say five people were killed and three injured. The company initially said seven were killed and 12 injured but now says only five were killed. The survivors say the numbers were much higher.

Regardless of the numbers, there is evidence that at least some of the victims were shot from behind as they were fleeing. Tundu Lissu, an opposition member of the Tanzanian Parliament and a longtime critic of Barrick, says the unofficial autopsies on four shooting victims show they were shot from behind.

Two injured survivors say the same. Nelson Charles, a 22-year-old who has scavenged rocks from North Mara for the past three years, is hiding from the police because of rumours that they will arrest anyone who was injured in the May 16 shooting. But when he is tracked down for a long interview, he lifts his arm to reveal his gunshot wound. The bullet entered the back of his arm and exited through the front, supporting his story that he was shot by police as he ran for his life. On that morning, he says, he was carrying only the tools of his trade: a hammer and a bottle of water to wash the waste rocks as he searched for traces of gold.

Maulidi Issa, who has made a living from the waste rocks for the past 11 years, was shot in the hand in the same incident. He says he was unarmed and fleeing when the bullet hit him. Two other witnesses agree that they saw no weapons among the intruders.

Barrick will not comment on details of the shooting, except to say that the police were under fierce attack when they opened fire. “We are aware that the police have highly unimpeachable evidence establishing that masses of intruders invaded the area from many directions, that the police attempted to repel them using gas while coming under sustained attack, that police attempted to retreat from oncoming invaders, and again used gas to attempt to halt the attack, before they were overwhelmed and forced to defend themselves with live ammunition,” the company said in a statement to The Globe and Mail.

The company continues to insist that machetes and other weapons were used against the police. But it would not give any estimate of the number.

Constantine Massawe, the regional police commander in Tarime, the region where the mine is located, gave a different account. Nobody attacked the police with machetes, and the seven injuries among the police were all caused by stones, he said.

Mr. Massawe said the police opened fire on the villagers because they were throwing stones at police vehicles when the police tried to disperse them. In the past, he said, the police would retreat when stones were thrown, but this time they decided to shoot. He said the police are now investigating “whether there was a necessity for shooting or not.”

Mr. Lissu, one of several politicians and journalists arrested by police in Tarime in the days after the shooting, said that while in jail he met more than 20 villagers who had also been arrested. They were charged only with theft of waste rocks, and none was charged with any weapons offences, he said.

Mr. Charles, the injured survivor, said he personally saw two people shot dead near him on May 16. One of them was a bystander who wasn’t even involved in rock scavenging, he said. “He was just wondering what was going on.”

He said he had been running away for several minutes when he was hit by the police bullet. “Everyone was running and shouting and trying to save their lives. It was a massacre. I was shocked – normally the police only shoot in the air.”

Figures provided by Barrick show that an average of about 800 people trespass on the mine site every day, and 70 stoning incidents were recorded in the first five months of this year alone. The company notes that it has signed an agreement with the Tanzanian police requiring its officers to use “only the minimum force necessary to control any violent situation” and requiring them to follow international human-rights standards.

In the past, the company erected a fence to keep out trespassers, but it was torn down by the villagers. Now it is planning to spend $14-million to build a three-metre-high concrete wall for 12 kilometres around all of the mine pits and waste heaps – topped by electrified razor wire.

The villagers predict that the concrete wall, too, will soon be breached. In this impoverished and remote region of East Africa, they believe that Barrick’s massive mountain of waste rocks is their only hope of economic survival – and they will do anything to keep it open.